Watershed Protection

The mission of the Denton Watershed Protection program is to maintain the quality of each watershed, ultimately protecting our water sources and the ecosystems within our watersheds.

What is a watershed?
A watershed is the area of land that catches rain and snow and drains or seeps into a marsh, stream, river, lake or groundwater, and eventually even to the ocean. Watersheds can range from acres to hundred or even thousands of square miles. Some watersheds extend across county, state, and even international borders. Just as creeks drain into rivers, watersheds are nearly always part of a larger watershed.

Why is watershed protection important?
Surface and groundwater resources are tied directly to all watersheds. Anything that can be picked up with rainfall runoff or any other drainage can end up in the watershed. This includes trash and pollutants that can upset the ecosystem and threaten our resources for water supply and recreation.

Areas of concern for watershed protection
Non-point source pollution is water pollution that originates from surprisingly common sources such as our homes, yards, cars and even our pets. It is generated by a variety of everyday activities and is Denton’s leading cause of water quality degradation. What may initially appear as harmless behaviors such as fertilizing, mowing, taking out the trash and walking the dog can clog or pollute a storm drain which drains to Lake Lewisville a primary source of drinking water for much of the DFW Metroplex.

What does Watershed Protection do?
The Watershed Protection division administers programs to reduce the overall pollutants within the surface waters of Denton and to ensure compliance with the National Pollution Discharge Elimination System (NPDES) Storm Water Phase II rule. In Texas, the Texas Commission of Environmental Quality (TCEQ) administers the Texas Pollution Discharge Elimination System (TPDES). As a TPDES phase II City, Denton operates and maintains a ‘municipal separate storm sewer system’ or MS4 for residents and businesses within the City of Denton.
Watershed Protection services include:

Through routine monitoring baseline conditions for the physical, chemical, and biological components of the city's surface water resources are established and monitored. Results from this monitoring program are used to support the requirements of the Phase II storm water program and assess water quality for the purposes of source water protection.

Cooper Creek, Hickory Creek, Pecan Creek and Clear Creek are the four main watersheds that convey water through Denton. Using topographical information, approximately 85 sub-basins have been delineated within the city. Sampling stations were established within these sub-basins at locations that would likely represent the water quality of the sub-basins. Monitoring of these sub-basins during base-flow conditions was initiated in January 2001 and has continued on a monthly basis ever since. Parameters analyzed in the tributary samples include flow status, temperature, dissolved oxygen, pH, conductivity, turbidity, salinity, litter index, visual evaluation and odor. Bimonthly, ten sampling stations are randomly selected for more intense analysis which included E. coli bacteria, metals, phosphorus, nitrogen, ammonia, nitrate, chlorides, sulfates, alkalinity, hardness, total solids and total suspended solids.

Permanent monitoring stations are established near the downstream ends of the three major watersheds (Hickory, Pecan and Cooper Creeks) prior to the confluences with Lewisville Lake and an additional station is established in Lewisville Lake near the drinking water intake. Real time monitoring is conducted at these locations by datasondes, an instrument with multiple sensors. These stations provide a more comprehensive assessment of the combined effects of sub-basin water quality just prior to entering the City's main drinking water source as well as near our primary drinking water intake on Lewisville Lake.

The data from the stream monitoring program are analyzed with the following objectives:

Characterize the general water quality condition of the stream

Identify illicit discharges

Identify long-term water quality trends

To learn more about the construction and industrial components of our program, visit the business Watershed Protection page.

What you can do to protect watersheds

Participate in Ten on Tuesday: Join hundreds of North Texas residents in preventing litter from reaching our waterways by picking up just 10 pieces of trash every Tuesday. It’s easy and effective — if, for just one year, 5,000 residents chunk 10 pieces of litter a week into the trash or recycling bin, the Metroplex will reduce litter by 2.6 million pieces!

Avoid Pollution: Properly dispose of used oil, antifreeze, paints, and other household chemicals with the City's free Home Chemical Collection program. Clean up spilled brake fluid, oil, grease, and antifreeze; but do not hose them into the street where they can eventually reach our water.

Pick up and properly dispose of pet waste: Pet waste can contain high levels of bacteria and pathogens that can be harmful to not only aquatic life, but to public health.

Volunteer: Each year, the City offers volunteer opportunities to help protect and maintain our water sources, such as Stream Clean, Great American Cleanup, and Texas Stream Team.

Report a spill. To report a spill or illegal dumping, call (940) 349-7745 (SPIL). If material spilled or dumped appears hazardous or is on fire, call 911.

Reduce trash from our waterways: Foster a litter-free Trinity watershed. The City of Denton is one of six metroplex cities that participates in the trash free trinity online mapping tool to promote and track trash removal activities in our region. The adopt-a-spot mapping tool is designed to facilitate / coordinate site adoptions for litter control.

​Watershed Residential FAQs

What is a Stormwater Management Plan?
The City of Denton has developed a Stormwater Management Plan (SWMP) as required by TXR040000. The SWMP outlines the goals, strategies and programs formulated to improve water quality, address existing and future conflicts between flooding and development, and preserve and enhance valuable natural resources. The recommendations will directly affect the City's capital improvement and operating programs. It describes the City’s responsibilities and authority regarding stormwater management implementation, and provides detailed descriptions of stormwater management BMPs.

What Is a Phase II Small MS4?
Phase I of the U.S. Environmental Protection Agency’s (EPA) stormwater program was promulgated in 1990 under the Clean Water Act (CWA). Phase I relies on National Pollutant Discharge Elimination System (NPDES) permit coverage to address stormwater runoff from incorporated places with a population of 100,000 or greater on the 1990 U.S. census and construction sites larger than five acres.

The Stormwater Phase II Final Rule is the next step in EPA’s effort to preserve, protect, and improve the nation’s water resources from polluted stormwater runoff. The Phase II program expands the Phase I program by requiring additional operators of Municipal Separate Storm Sewer Systems (MS4s) in urbanized areas and operators of small construction sites, through the use of NPDES permits, to implement programs and practices to control polluted stormwater runoff. Phase II is intended to further reduce adverse impacts to water quality and aquatic habitat by instituting the use of controls on the unregulated sources of stormwater discharges that have the greatest likelihood of causing continued environmental degradation.

What Are the Phase II Small MS4 Program requirements?
Operators of regulated small MS4s are required to design their programs to:

Reduce the discharge of pollutants to the maximum extent practicable" (MEP);

Protect water quality; and

Satisfy the appropriate water quality requirements of the Clean Water Act

Implementation will typically require the development and implementation of Best Management Practices and the achievement of measurable goals to satisfy each of the six minimum control measures.

Public Education, Outreach and Involvement

Illicit Discharge Detection and Elimination

Construction Site Stormwater Runoff Control

Post-Construction Stormwater Management in New Development and Redevelopment

Pollution Prevention / Good Housekeeping for Municipal Operations

Industrial Stormwater Sources (if serves population more than 100,000)

Additional information on our construction site stormwater and industrial site stormwater programs can be found on our business webpage.

Federal regulations define an illicit discharge as “...any discharge to an MS4 that is not composed entirely of stormwater...” with some exceptions. These exceptions include discharges from groundwater, NPDES-permitted industrial sources, fire-fighting activities, water line flushing and air conditioner condensate. Illicit discharges are considered “illicit” because MS4s are not designed to accept, process, or discharge such non-stormwater wastes.

Common sources of illicit discharges:

Sanitary Wastewater

Effluent from septic tanks

Car wash wastewaters

Improper Oil disposal

Radiator flushing disposal

Laundry wastewaters

Swimming pool filter backwash and pool discharges

Spills from roadway accidents

Improper disposal of auto and home toxic chemicals

Illicit discharges often enter the system through storm drain inlets. The result is untreated discharges that contribute high levels of pollutants, including heavy metals, toxics, oil and grease, solvents, nutrients, viruses, and bacteria to receiving waterbodies. Pollutant levels from these illicit discharges have been shown in EPA studies to be high enough to significantly degrade receiving water quality and threaten aquatic, wildlife, and human health.

What is required?
Recognizing the adverse effects illicit discharges can have on receiving waters, the Phase II rule requires an operator of a regulated small MS4 to develop, implement, and enforce an illicit discharge detection and elimination program. This program must include the following:

A storm sewer system map, showing the location of all outfalls and the names and location of all waters of the United States that receive discharges from those outfalls.

Through an ordinance, or other regulatory mechanism, a prohibition (to the extent allowable under State, Tribal, or local law) on non-stormwater discharges into the MS4, and appropriate enforcement procedures and actions.

A plan to detect and address non-stormwater discharges, including illegal dumping, into the MS4.

The education of public employees, businesses, and the general public about the hazards associated with illegal discharges and improper disposal of waste.

The determination of appropriate best management practices (BMPs) and measurable goals for this minimum control measure.

Municipal Good Housekeeping for municipal operations minimum control measure is a key element of the small MS4 stormwater management program. This measure requires the small MS4 operator to examine and subsequently alter their own actions to help ensure a reduction in the amount and type of pollution that: (1) collects on streets, parking lots, open spaces, and storage and vehicle maintenance areas and is discharged into local waterways; and (2) results from actions such as environmentally damaging land development and flood management practices or poor maintenance of storm sewer systems.

What is required?

Recognizing the benefits of pollution prevention practices, the rule requires an operator of a regulated small MS4 to develop and implement an operation and maintenance program with the ultimate goal of preventing or reducing pollutant runoff from municipal operations into the storm sewer system.

Include employee training on how to incorporate pollution prevention/good housekeeping techniques into municipal operations such as park and open space maintenance, fleet and building maintenance, new construction and land disturbances, and stormwater system maintenance.

Determine the appropriate best management practices (BMPs) and measurable goals for this minimum control measure.

As development increases in urban areas, natural landscapes are altered. Grasslands and forests are removed along with their natural abilities to stabilize the existing landscape. Natural features are replaced with impervious surfaces such as concrete and asphalt. The ability for stormwater to naturally soak into the ground is then reduced and the increased quantity of stormwater runoff can contribute to flooding and can transport urban pollutants such as fertilizers, pesticides, oils, animal wastes and trash to our streams and rivers. These bodies of water serve as sources of our drinking water, so it is very important to be proactive and protect them from the impacts of urbanization.

In 2002, the North Central Texas Council of Governments, a voluntary association of more than 60 local governments in the North Central Texas region, developed iSWM (integrated Stormwater Management) Program with the help of Freese and Nichols, Inc. The iSWMTM program is a cooperative initiative that assists cities and counties in the North Central Texas region in achieving their goals of protecting local water resources.

The iSWM Program is designed to 1) encourage environmentally sustainable development and design for the long term and 2) address the impacts of urbanization during the temporary construction phase.

The iSWM Program for Development consists of three primary focus areas using the principles of Green Infrastructure and Low Impact Development to protect, restore, or mimic the natural water cycle. The first area of focus deals with protecting water quality. The goal of this measure is to simply remove pollutants in stormwater. This can be achieved through either 1) the preservation of natural features that can effectively filter out pollutants, 2) the construction of features onsite which can treat pollutants, or 3) the implementation of measures downstream that can mitigate pollution.

The second area of focus is designed to protect streambanks from the increase in water velocity that causes erosion. This can be achieved through either 1) downstream reinforcement or stabilization, 2) installation of onsite stormwater controls, or 3) the controlled release of excessive amount of stormwater.

The third area of focus addresses flood mitigation and the transport of floodwaters to minimalize local flooding. This can be achieved through either 1) providing adequate downstream systems to safely convey floodwaters, 2) installing onsite stormwater controls, or 3) simply maintaining existing conditions onsite.

The iSWM Program for Construction addresses stormwater runoff while construction is in process. Temporary controls that are used to do this are called Best Management Practices (BMPs). These measures are designed to 1) proactively prevent soil erosion on-site, 2) capture sediment on-site when erosion prevention is not feasible and 3) prevent construction materials and wastes from contaminating stormwater.

The City of Denton has been recognized as a regional leader in the efforts to protect our water resources. Currently, the City of Denton is recognized as a Silver Level Participant in the iSWM Program and is committed to improving quality of life and protecting the environment while creating economic opportunities for its citizens, businesses and institutions. The City of Denton also has adopted iSWM as part of it Engineering Drainage Criteria.

Benefits of iSWM include but are not limited to the following:

keeps safe from the effects of flooding

protects property values by reducing the effects of streambank erosion,

improves water quality

helps local governments address issues of water resources protection and compliance with state and federal regulations

Currently, more than 60 local governments are participating in the iSWM program in order to proactively mitigate the effects of urban development in the region. Find more about iSWM at http://www.iswm.nctcog.org/.

MOre You can do

DID YOU KNOW?
The average dog generates a quarter pound of feces a day? This may not sound like much, but it means that a watershed of 100,000 people has more than two and half tons of feces deposited into it EACH DAY ... that adds up to almost two million pounds per year!

WHY SHOULD YOU CARE?
An estimated 1.2 million dogs live in the North Texas area. Alone, each dog doesn’t “doo” that much, but collectively, it causes big problems!

Stormwater runoff can pick up and carry any pollutants that are left on the ground and deposit the into the City’s stormwater system. Stormwater is not treated, so that means whatever goes down the drain, such as chemicals, fertilizers, sediment and pet waste, will end up in our local streams, creeks and Lewisville Lake. Pet waste can contain high levels of bacteria, nutrients and pathogens that can be harmful to not only aquatic life, but public health. By picking up and disposing of pet waste properly, the amount of fecal pathogenic pollution can be decreased.

Pet waste is not only smelly and unsightly, but it also poses health risks for pets and people and is a water contaminant. Microorganisms causing health issues (including ampylobacteriosis, cryptosporidium, toxocariasis, parvovirus, and roundworms) can remain in the soil for up to four years if not cleaned up.

Pollutants from pet wastes (fecal coliforms, nitrogen) can be washed into streams and lakes from storm drains by rain or irrigation. This can make water unattractive or even unsafe for swimming, boating, fishing, and drinking.

WHAT SHOULD YOU DO?

Flush it: Pick up the waste with a scooper and flush it in a toilet.

Toss it: Place the waste in a plastic grocery bag, tie the end securely, and place it in your green trash cart.

Bury it: Scoop the waste and bury it at least six inches underground, away from gardens and water sources.

Texas Stream Team is a network of trained citizen monitors and supportive partners working together to gather information about the natural resources of Texas and to ensure the information is available to all Texans. Established in 1991, Texas Stream Team is administered through a cooperative partnership between Texas State University, the Texas Commission on Environmental Quality (TCEQ), and the U.S. Environmental Protection Agency (EPA). Currently, hundreds of Texas Stream Team citizen monitors collect water quality data on lakes, rivers, streams, wetlands, bays, bayous, and estuaries in Texas. Denton is a Texas Stream Team Partner, meaning we offer annual training sessions and have loaner sampling kits. Additionally we support the advanced training sessions which cover nutrient (nitrogen and phosphorus) and bacteriological monitoring.

We all take pride in the appearance of our homes and yards. However, blowing leaves into the gutter or dumping them into drainage ditches are autumn activities with potentially serious consequences.

They have to go somewhere. Leaves and yard debris that are blown into the street eventually collect in the storm drains. During heavy rains, clogged storm drains and bar ditches can cause flooding. The Drainage Department dispatches a Street Sweeper on a schedule that takes about six months to make a full pass through the City. On a good day the sweeper can pick up around 40 cubic yards...or about 40 pickup truck loads. That's a lot of yard waste to send to the Landfill.

Mulching is an easy and beneficial way to deal with leaves. Just mow and leave on your lawn. Composting is another alternative, you can have home grown fertilizer ready for planting. You can bag yard waste and place on the curb with trash pick-up for recycling into Dyno Dirt.

Cleanouts are the pipes that allow access to a home or business’s sewer service. They are usually covered by white plastic caps that protrude above the top of the cleanout pipe.

People often mow over these caps, breaking off the top. This allows rainwater to flow in through open cleanouts, which can overwhelm sewer system pipes, cause overflows, and cost more money to carry this excess water to the wastewater plant and treat it.

It is a homeowner's responsibility to install a sewer cleanout if one is not present. If you have a cleanout, City Code Section 26-188 requires that you maintain your cleanout by keeping it capped.

Did you know swimming pool water can pollute our creeks, streams, and lakes? Even though it is safe for us, swimming pool water may contain chemicals that are harmful to aquatic life. Anything discharged into streets or storm drains goes directly to the nearest creek, stream, or lake without being treated. With the average pool holding about 19,000 gallons, improper disposal can adversely impact our waterways. Pools have a high concentration of chlorine which is toxic to fi sh and wildlife.

To prevent algae, many pools are treated with an algaecide, often containing copper or silver which can hinder natural plant growth along streams.

Where should I drain the water from my pool?

Into your landscape for irrigation. Pools may be discharged onto your property if the water does not run off into streets or cause stagnant water.

Into the sanitary sewer system via your home’s sewer clean-out. The sewer clean-out is usually a threaded cap about three to four inches in diameter.

After approval by the Watershed Protection Department, into the storm drain system. Watershed Protection can be reached at (940) 349-7123 or (940) 349-7153 or send an email to Watershed@cityofdenton.com.

To obtain permission, pool water will have to meet the following criteria:

Discontinue use of pool chemicals at least three days prior to discharge

Dechlorinate water to non-detectable level of chlorine (< 0.1 mg/L)

Clean any vegetation and debris from pool

Monitor discharge rate to prevent erosion

Freshwater pool water only (saltwater pools cannot be discharged to the storm drain)

Where can I discharge pool filter backwash water?

Swimming pool filter backwash should be discharged to the sanitary sewer. Though low in volume, it has a higher concentration of contaminants compared to pool water.

Denton City Code of Ordinances Ch. 26-189 prohibits discharge of pollutants to storm sewer or natural outlet except where suitable treatment has been provided or where a Federal National Pollution Discharge Elimination Systems (NPDES) permit is issued. Fines for violating section 26-189 of the City Code could equal up to $2,000 per violation, per day.